It surely has to be the Rock. Can't see it being Bryan as you'd expect a powerhouse to come in, Bryan, as popular as he may be, coming in and beating Strowman, will take legitimacy away from the big guy. Wouldn't mind seeing them tag up with someone like Orton and having the Wyatts go over, then building up to Survivor Series (or Hell in a Cell) with the return of The Rock, with much bigger build up though. Admittedly, don't think it's plausible.